The unintentional separation of a child from a parent, and worse, the outright abduction of a child has been a serious and increasing problem in the U.S. as well as abroad. It has been noted that abduction occurs more often than not in situations wherein the child is in the immediate proximity of a parent. However, because the parent may be otherwise preoccupied, distracted, or has a momentary lapse in attention directed to the child, the child is permitted to stray away from the parent. Common scenarios involve the parent and child walking through a department store, a crowded mall or amusement park. In a moment of inattention by the parent, as he or she may be focusing on a particular item in a store, a display or locating a particular ride or facility, the child may accidentally wander away and becomes abducted. Another scenario may involve a child, in an attempt to explore his surroundings during an activity, such as bike riding or hiking, proceeding far more ahead of the parent than normally permitted. These are but a few examples. However, with the lifestyle of many young families becoming more and more active, the potential for abduction greatly increases.
Approaches to parent-child security have varied in detail ranging from mechanical tethers or physical restraints, similar to a pet leash, to different combinations of separation detectors and signaling devices for remote control and alarm devices. For example, one existing system includes a harness, to be placed on the child, and an extension cord attached to the harness and to be held or worn on the wrist of the parent. This system, although effective, can limit the range that a child may be separated from the parent. The system can also be cumbersome and difficult to manage, particularly in a crowd, as the extension cord must be maneuvered around people should there be any distance between the parent and child. The extension cord may further trip those in the crowd or bring additional dangers to those in the crowd.
Several known devices trigger an alarm when two units (a detector unit and a transmitter unit) are separated by more than a preset distance. For example, one system discloses a device to deter kidnapping of a child. The system generates a signal at the transmitter unit and provides for an alarm trigger at the child unit. This and other similar systems are based on proximity or separation sensing, and may offer little added functionality, such as two-way communications, adaptive alarming or child panic provisions. The power output and hence range of a pure proximity transmitter may also be limited by regulations set forth by the Federal Communications Commission. As such, these systems do not permit for a very large proximity range, and can often be encumbered by frequent false alarms as a result. Moreover, such systems are frequently provided only with an alarm-on and alarm-off state. Accordingly, the parent is permitted little or no discretion in terms of varying proximity range or other functionalities to adapt to different environments.
There remains, therefore, a need for a spatial monitoring and security system that is convenient in use, relatively free from false alarms, functional over a relatively large range, and affords both the parent and the child the ability to page one another or issue an alarm in a panic situation.